Dynamical Photon Spheres in Charged Black Holes and Naked Singularities

Abstract

To understand the nature of a black hole shadow in dynamical spacetimes, we construct an analytical model of a dynamical photon sphere in the context of the Bonnor-Vaidya spacetime. Comparing the resulting photon sphere radius with the one in Vaidya spacetime, we find that the charge always decreases the radius of the photon sphere. We also prove that a naked singularity in Bonnor-Vaidya spacetime, unlike the static Reissner-Nordstrom naked singularity, may cast a shadow, and as a result, it cannot be distinguished from a black hole through its shadow.

10 pages

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Cited by in corpus (12)

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• Perturbations of the Vaidya metric in the frequency domain: Quasi-normal modes and tidal response
• Exact Regular Black Hole Solutions with de Sitter Cores and Hagedorn Fluid
• Formation of regular black hole from baryonic matter
• Regular Black Hole Models in the Transition from Baryonic Matter to Quark Matter
• Analyzing the Influence of Geometrical Deformation on Photon Sphere and Shadow Radius: A New Analytical Approach -Stationary, and Axisymmetric Spacetime
• Analytical approach for calculating shadow of dynamical black hole
• Generalized Vaidya Spacetime in Cotton and Conformal Killing Theories
• Homothetic Killing horizons in generic Vaidya spacetimes
• Probing Weak-Force Corrections to Black Hole Geometry via Long Range Potentials: Feinberg-Sucher and Ferrer-Nowakowski Potentials